Most of us do not how how to figure out this number without performing the actual rep itself. Use this easy calculator to get a basic idea of how much weight you can lift once.

The problems with finding your 1 rep max by doing the actual reps:

If you do too many warm up sets or too many attempts, your 1 rm will be lower due to fatigue.

If you are having a bad day either in life or in the gym, your 1 rm will be lower due to stress.

If you are using steroids or supplements, your 1 rm will be higher due to the supplementation.

What I have provided here for you today, is a simple 1 rm calculator. Simply plug in the weight you used and the number of reps you completed before failure, without assistance, and you will have an idea of what your 1 rm is.

The problems with the calculator:

Everyone’s body is different. If you are built for endurance, the calculator result will be too high.

If you are built for absolute strength and explosive power, the calculator result will be too low.

You should use 3 different weights at 3 different rep ranges, and average those numbers to get a closer approximate result.

1 Rep Max Calculator

Like I said, these numbers could be off depending on the way you train and your genetics. They are probably accurate within 10-20 pounds on either side, but these are the numbers I would suggest using in a weight lifting program, if you don’t already know your 1 rep max or any of the other percentages. Now go lift!